Diaphragm assembly for pressure operated pilot controlled shutoff valve

ABSTRACT

Fluid pressure operated pilot controlled diaphragm valve. The diaphragm forming the valve has a marginal sealing portion, an annular thin-walled bellowslike portion extending radially inwardly of the sealing portion and a disclike central portion extending inwardly of the thin-walled bellowslike portion. A plastic insert rigidly backs up the disclike portion of the diaphragm and has a guide boss leading through the disclike portion of the diaphragm, having a central pilot orifice leading therethrough. The insert has a bleed hole of smaller crosssectional area than the cross-sectional area of the pilot orifice leading therethrough. The diaphragm has a series of bleed holes leading therethrough. A communicating passageway is provided between the bleed holes in the disclike portion of the diaphragm and the bleed hole leading through the plastic insert. The bleed holes leading through the diaphragm serve as a screen to prevent dirt from clogging the bleed hole leading through the plastic insert.

United States Patent [72] inventors Paul A. Dolter Roselle; William R.McCarty, Jr., Skokie; Wesley S. Swanson, Elk Groove Village, all of,I11. [21] Appl. No. 850,572 {22] Filed Aug. 15,1969 [45] Patented July20, 1971 [73] Assignee Eaton Yale 8; Tone, Inc.

Cleveland, Ohio i [54] DIAPHRAGM ASSEMBLY FOR PRESSURE OPERATED PILOTCONTROLLED SHUTOFF VALVE 10 Claims, 7 Drawing Figs.

[52] U.S.Cl 251/30, 251/38 [51] Int. Cl F16k3l/385,

F 16k 31/40 [50] Field ofSearch ..l 251/30, 38, 368, 39

[56] References Cited UNlTED STATES PATENTS 2,017,840 10/1935 Brooks251/38 2,870,986 1/1959 Vargo.... 251/30 X 2,936,780 5/1960 Pratt 251/38X 3,385,560 5/1968 Hare. 251/368 X 3,439,896 4/1969 Worst. 251/38FOREIGN PATENTS 1,401,763 4/1965 France 251/30 625,605 7/1949 GreatBritain. 251/30 1,141,240 l/l969 Great Britain 251/30 PrimaryExaminer-Arnold Rosenthal Attorney-Hill, Sherman, Meroni, Gross andSimpson ABSTRACT: Fluid pressure operated pilot controlled diaphragmvalve. The diaphragm forming the valve has a marginal sealing portion,an annular thin-walled bellowslike portion extending radially inwardlyof the sealing portion and a disclike central portion extending inwardlyof the thin-walled bellowslike portion. A plastic insert rigidly backsup the disclike portion of the diaphragm and has a guide boss leadingPATENTEU JuLzolsn 3.593957 sum 2 OF 2 6' INVENTORS Pilot controlledpressure operated diaphragm valves controlled by a pilot valve, whichmay be the solenoid of an armature, have frequently been used to controlthe flow of fluid in appliances and like apparatus. Such valves haveincluded a diaphragm having a marginal sealing portion, a thin-walledannular bellowslike'portion leading radially inwardly of the sealingportion and a thickened central portion having a central orifice leadingtherethrough, selectively closed by the pilot valve. One or two bleedholes of a smaller cross-sectional area than the cross-sectional area ofthe central orifice have been provided, leading either through thebellowslike portion of the diaphragm or through the central thickenedportion of the diaphragm. Where the bleed hole leads through the bel'lowslike portion of the diaphragm, or the central thickened portion ofthe diaphragm, it is subject to distortion and erosion, with the resultthat the cross-sectional area of the central pilot orifice in time willbecome less than the cross-sectional area of the bleed hole. The mainflow of fluid through the valve will then be closed off by flow throughthe bleed hole,

and the valve will not open.

Also, where the cross-sectional area of the bleed hole becomes cloggedor blocked by dirt, there will not be sufficient pressure on top of thevalve to effect closing of the valve even when the central orificeleading through the valve remains closed.

In the design of pilot controlled pressure operated valves, it isadvantageous for the central pilot orifice to be relatively close to thecross sectional area of the bleed hole, in order to reduce the forcerequirement of the solenoid coil, controlling which formerly leadthrough the diaphragm, the bleed hole of necessity, being of arelatively small diameter, is subject to clogging by dirt.

SUMMARY AND OBJECTS OF THE INVENTION In the present invention we remedythe foregoing disadvantages heretofore present in pressure operatedpilot controlled diaphragm valves by providing a plurality of screeningholes leading through the thickened portion of the diaphragm, andproviding a bleed hole of a smaller crosssectional area than the pilotorifice leading through a reinforcing insert for the valve, with acommunicating passageway between the screening holes, leading throughthe thickened portion of the diaphragm to the bleed hole leading throughthe plastic insert.

We further contemplate the provision of a filtering or screening mediumin the communicating passageway, to further obviate the collection ofdirt in the bleed hole leading through the plastic insert.

A principal object of the present invention, therefore, is to provide animproved form of diaphragm assembly arranged with a view towardpreventing clogging or obstruction of the bleed hole, providing pressureto close the valve.

' A further object of the invention is to improve upon the diaphragmsheretofore used in pilot controlled pressure operated diaphragm valvesby backing up the central portion of the diaphragm by a plastic inserthaving a central pilot orifice leading therethrough and at least onebleed hole spaced radially outwardly of the pilot orifice, and byproviding a plurality of screening holes leading through the thickenedportion of the dlaphragmand a filtering passageway means between thescreening holes leading through the diaphragm and the bleed holeleadingthrough the plastic insert.

invention.

A further object of the invention is to improve upon the diaphragmsheretofore used in pilot controlled pressure operated diaphragm valvesby backing the central portion of the valve with a plastic insert havinga central pilot orifice leading therethrough and a bleed hole spacedradially outwardly of the pilot orifice, and by providing a screen inthe insert in registry with the bleed hole leading through the orificeand providing a series of holes leading through the central thickenedportion of the diaphragm, and having communication with the screeningmeans and bleed holes leading through the plastic insert;

Still another object of the invention is to provide a novel and improvedform of diaphragm for pilot controlled pressure operated diaphragm valvein which the central portion of the diaphragm is backed by a plasticinsert, having a central pilot orifice leading therethrough, and havinga radially outwardly spaced bleed hole leading through the plasticinsert, in which a screening means affords communication between thecentral thickened portion of the diaphragm and the bleed hole, and is soarranged as not to be subject to swellor erosion of the material fromwhich the diaphragm is made and to provide the rigidity in the diaphragmfor efiicient operation thereof.

Other objects, features and advantages of the invention will be readilyapparent from the following description of preferred embodimentsthereof, taken in conjunction with the accompanying drawings, althoughvariations and modifications may be effected without departing from thespirit and scope of the novel concepts of the disclosure.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial fragmentarycross-sectional view taken through a pilot controlled pressure operateddiaphragm valve constructed in accordance with the principles of thepresent FIG. 2 is a bottom plan view of a plastic reinforcing insertforthe' diaphragm, drawn to an enlarged scale, and illustrating certainprinciples of the present invention.

FIG. 3 is a transverse sectional view taken through the insert shown inFIG. 2.

FIG. 4 is a fragmentary cross-sectional view taken through the diaphragmand insert, illustrating a modified form in which the invention may beembodied.

FIG. 5 is a cross-sectional view taken through a diaphragm and insertillustrating still another form in which the invention maybe embodied.

FIG. 6 is a bottom plan view looking at the thickened portion of thediaphragm shown in FIG. 5 from the bottom thereof; and

F IG. 7 is a cross-sectional view taken through a diaphragm and insertconstructed in accordance with the principles of the present invention,and illustrating still another modification of theinyention.

DESCRIPTION OF PREFERRED EMBODIMENTS OF INVENTION In FIGS. 1, 2 and Elof the drawings, a pressure operated pilot controlled diaphragm mixingvalve of a type particularly adapted for use in appliances is shown ascomprising a valve body 10 having an inlet 11 leading thereinto and anoutlet 12 leading therefrom. The valve shown may be a single shutoffvalve. One valve only, therefore, need be shown and described herein.The valve body 10 has at least one cavity 13 therein, containing adiaphragm shutoff valve 15 and having an annu- Iar sealing groove 16extending about an annular inlet passageway 17, for receiving a sealinghead 19 of the diaphragm 15. i

The diaphragm 15 may be made from rubber or one of the well-knownsubstitutes for rubber and is shown in FIG. 1 as being seated on anannular port 20 on a central annular disklike portion 21 of thediaphragm. The outer margin of the disklike portion of the diaphragmterminates into an upwardly extending bellowslike convolution 22extending along the outer margins of a plastic insert and backing member23, for the central disklike portion of the diaphragm. The convolution22 is connected with the sealing bead l9 and forms an integral partthereof.

The sealing bead l9is retained in sealing engagement with the sealinggroove 16 as by an armature guide 24, retained to the valve body by aretainer plate 25, as shown and described in an application Ser. No.816,714, filed by William R. McCarty, Jr. on Apr. 16, I969 and entitledShuboff off Valve and Armature Guide Therefor," so not herein shown ordescribed in detail. The armature guide 24 forms a guide for an armature26 having a pilot valve 27 at its lower end cooperating with a pilotorifice 29 leading through the center of the plastic insert 23 tocontrol opening and closing of the valve. The armature 26 is biased by aspring 30 to engage the pilot valve 27 with the orifice 29 and is movedout of engagement with said orifice by energization of a solenoid coil31, encircling said armature, in a conventional manner.

The inside of the armature guide 24 is spaced from the diaphragm l5 andinsert 23 and with said diaphragm and insert forms a pressure chamber 32for the building up of fluid under pressure from the inlet 11 to effectclosing of the valve upon closing of the pilot orifice 29 by the pilotvalve 27, and the flow of fluid from the inlet into the chamber 32through a bleed orifice 33, leading through the insert 23.

The thickened central portion of the diaphragm also has a plurality ofscreening holes or orifices 35 leading therethrough, shown as being onthe same circumferential line as the bleed hole 33, and leading to anannular downwardly opening groove 36 in the insert 23, and havingcommunication with the screening holes 35 and with the bleed hole 33, tosupply inlet fluid to flow through said bleed hole and maintain thevalve closed as the plot valve 27 closes the central orifice 29. Thegroove 36 is thus sealed to the thickened portion 21 of the diaphragm 15by engagement of the thickened portion of said diaphragm with ashouldered portion 37 of said insert. The insert 23 is secured to thediaphragm 15 by flexing the diaphragm over and about a depending guideportion 39 of said insert into the groove forming the shouldered portion37 of said insert. Said guide portion 39 is adapted to have guidingengagement with the interior portion of the outlet 12.

With the construction just described, the annular groove 36 leading tothe bleedhole 33 and supplied with inlet pressure from any one or all ofthe screening orifices 35 enables the insert to be readily assembled tothe rubber diaphragm and to are of sufficient diameter that the valvewill operate with only one unclogged screening hole in the diaphragm,and that the only way large pieces of dirt can cause a problem is byclogging all of the screening holes 35.

It may further be understood that the diaphragm assembly just describedprovides a fine filtering device, located where required withouthindering the main flow of fluid through the valve, and where the mainflow of fluid through the valve can actually flush and cleanse thescreening holes 35 each time the valve is opened.

In the form of the invention illustrated in FIG. 4, we have shown adiaphragm 40 similar to the diaphragm l5, and having a plurality ofscreening holes 41 leading therethrough, having communication with anannular channel 42 opening to the undersurface of a plastic insert 43.The insert 43 is similar to the plastic insert 23, but is shown ashaving a single bleed orifice 44 leading therethrough, to supply fluidto maintain the valve closed as the pilot valve 27 closes a centralpilot orifice 45, leading along said insert.

The foregoing modification operates in the same manner of the form ofthe invention illustrated in FIGS. I, 2 and 3, but simplifies themolding of the plastic insert and also simplifies the punching ormolding of holes in the diaphragm, since the cross-sectional thicknessof the rubber along the annular groove 42 is reduced. The screeningaction of the diaphragm valve, operates in the same manner as in theform of the invention illustrated in FIGS. I, 2 and 3. i

In FIGS. 5 and 6 of the drawings, we have shown a three piece diaphragmvalve assembly having a screen 50 molded in a thickened portion 51 of adiaphragm 52, similar to the diaphragms l5 and 40. The screen 50 isshown in FIG. 5 as molded between the top and bottom portions of thethickened portion of the diaphragm in an annular channel 53, havingcommunication with a single bleed hole 55 leading through a plasticinsert 56. Ribs 57 extend across the annular channel 53 free from thescreen, to accommodate the passage'of fluid through the screen and bleedhole 55, to effect closing of the valve by pressure upon closing of acentral pilot orifice 59 by the pilot valve 27.

The screen 50 may be a plastic or metal screen or a metal washer havinga series of fine holes punched or drilled therein and eliminates theproblems of hole size changes due to swelling of the rubber of thediaphragm, or deterioration of the diaphragm, inherent in rubberdiaphragms.

In FIG. 7 of the drawings, we have illustrated still another modifiedform in which the invention may be embodied. This form of the inventionis similar to the form illustrated in FIGS. 5 and 6 except an annularscreen 60 is molded or otherwise mounted in the undersurface of aplastic insert 61 for a diaphragm 64 and has communication with anannular passageway 62 communicating with a bleed orifice 63 leadingthrough said insert. The diaphragm 64, like the diaphragms 15, 40 and52, has a plurality of relatively large holes 65 extending therethroughin communication with an annular channel 66 communicating with thescreen 60 and channel 62.

While a channel 66 is herein shown, this channel need not necessarily beprovided as long as the holes 65 lead to the screen 60 and channel 62.The channel 66, however, may aid in flushing dirt from the undersurfaceof the screen. The holes 65 are also designed to be large enough to beunaffected by swell or deterioration of the rubber of the diaphragm.

The screening shown in FIGS. 5, 6 and 7 may be of a small mesh and lowerthe incidence of the armature or pilot valve jamming in its guide, andthereby permit closer clearances between the guide and armature and anincrease in the armature mass, with a resultant increase in theefficiency of the magnetic circuit, where the valve is solenoidoperated.

With the structure just described, a smaller bleed orifice leadingthrough the plastic insert may be provided than has heretofore beenpractical, giving the valve a slower close-off rate, and therebyreducing water hammer and premature failure of the plumbing, caused byhigh pressure shocks, and permitting the use of a smaller central pilotorifice and thereby reducing the force required to operate the valve,with a resultant reduction in cost of the valve.

The screening of the dirt from the chamber 32 before it reaches thearmature guide and pilot valve also reduces wear of the guide by thereciprocating armature and reduces wear at the inner face of the plasticinsert with the convolution 22 of the diaphragm and prevents particlesof dirtfrom becoming imbedded in the pilot valve and thereby reducesfailure in closing of the valve, as well as reducing erosion caused byentrained dirt in the fluid as it passes through the bleed orifice of arelatively rigid insert backing up said disklike central por tion andhaving a disklike portion reinforcing said diaphragm, on one sidethereof and t V a central guide portion extending through said diaphragmbeneath said disklike central portion of said diaphragm and havingguiding engagement with said outlet passageway,

a central pilot orifice leading through said central guide portion ofsaid insert and having communication with said outlet,

an armature having a valve on the end thereof cooperating with saidcentral pilot orifice, to open and close said orifice,

a solenoid coil. energizable to move said armature to open said orifice,

bleed means leading through said diaphragm and said insert and providingpressure to close and maintain said valve closed upon closing of saidpilot orifice by said armature,

said bleed means comprising a plurality of circumferentially spacedscreening holes leading through said diaphragm,

I a single bleed hole leading through said insert and of smaller.cross-sectional area than the cross-sectional area of said central plotorifice, and

passageway means between said circumferentially spaced screening holesand said single bleed hole leading through said insert.

2. The solenoid controlled fluid pressure operated diaphragm shutoffvalve of claim 1, wherein the insert is a plastic insert, and

- wherein the passageway means is an annular passageway in the disklikecentral portion of said diaphragm and communicates with said screeningholes and has communication with said central bleed hole leading throughsaid in- 3. The solenoid controlled fluid pressure operated diaphragmshutoff valve of claim I,

wherein the insert is a plastic insert, and

wherein the passageway means between said circumferentially spacedscreening holes leading through said diaphragm and said single bleedhole leading through said insert comprise an annular passageway in saidinsert having communication with said bleed hole in said insert andopening to said diaphragm and having communication with saidcircumferentially spaced screening holes.

4. The solenoid controlled fluid pressure operated diaphragm shutoffvalve of claim 1,

wherein the circumferentially spaced screening holes lead ing throughsaid diaphragm comprise a screen molded in the disklike central portionof said diaphragm and an annularpassageway leading from said screen andhaving communication with said bleed hole leading through said insert.5. The solenoid controlled fluid pressure operated diaphragm shutoffvalve of claim 1,

wherein the communicating passageway means between said screening holesleading through said diaphragm and said bleed hole leading through saidinsert, comprise an annular passageway in said insert opening to saiddiaphragm and a screening in said annular passageway and havingcommunication with said screening holes leading through said diaphragm.6. A flexible diaphragm valve made from a resilient material andparticularly adapted for a pilot controlled pressure operated valve,comprising,

a diaphragm having a peripheral sealing portion, an inner annularbellowslike portion and a central disklike portion forming a shutofivalve, I a rigid plastic insert backing up said central disklike portionand sealed thereto, said annular bellowslike portion extending about theperiphery of said plastic insert and outwardly therefrom and terminatinginto said peripheral sealing portion, said insert having a central guideboss leading through said central disklike portion of said diaphragm,having a central pilot orifice leading therethrough, and having onebleed hole spaced radially of said central pilot orifice and of a lessercross-sectional area than the cross-sectional are of said central pilotorifice, a plurality of circumferentially spaced screening holes leadingthrough said disklike portion of said diaphragm, and communicatingannular passageway means between said screening holes and said bleedorifice.

7. A flexible diaphragm in accordance with claim 6,

wherein the communicating passageway means is an annular passageway inthe insert and opening to said screening holes and having communicationwith said bleed orifice.

8. A flexible diaphragm in accordance with claim 6,

wherein the communicating passageway means is an annular passageway insaid central disklike portion of said diaphragm and opening to saidinsert.

9. A flexible diaphragm in accordance with claim 6,

wherein the screening holes in said diaphragm comprise a screen moldedin said central disklike portion of said diaphragm and an annularpassageway in registry with opposite sides of said screen and with saidbleed hole lead ing through said orifice.

10. A flexible diaphragm in accordance with claim 6,

wherein the communicating passageway means comprises an annularpassageway in said insert, opening to said disklike portion of saiddiaphragm, and having a screen ex tending thereabout.

1. In a solenoid controlled pressure operated diaphragm shutoff valve, avalve body having a valve cavity therein, an inlet passageway opening tosaid cavity and having communication with a source of fluid underpressure, an outlet port, an annular valve seat disposed radiallyinwardly of said inlet passageway and having communication with saidoutlet port, an annular sealing groove extending about said outlet port,a flexible diaphragm cooperating with said annular valve seat to controlthe flow of fluid between said inlet passageway and said outletpassageway and sealed along its margin in said sealing groove, saiddiaphragm having a thin-walled bellowslike annular portion disposedinwardly of its peripheral portion and a disklike central portion, arelatively rigid insert backing up said disklike central portion andhaving a disklike portion reinforcing said diaphragm, on one sidethereof and a central guide portion extending through said diaphragmbeneath said disklike central portion of said diaphragm and havingguiding engagement with said outlet passageway, a central pilot orificeleading through said central guide portion of said insert and havingcommunication with said outlet, an armature having a valve on the endthereof cooperating with said central pilot orifice, to open and closesaid orifice, a solenoid coil energizable to move said armature to opensaid orifice, bleed means leading through said diaphragm and said insertand providing pressure to close and maintain said valve closed uponclosing of said pilot orifice by said armature, said bleed meanscomprising a plurality of circumferentially spaced screening holesleading through said diaphragm, a single bleed hole leading through saidinsert and of smaller cross-sectional area than the cross-sectional areaof said central pilot orifice, and passageway means between saidcircumferentially spaced screening holes and said single bleed holeleading through said insert.
 2. The solenoid controlled fluid pressureoperated diaphragm shutoff valve of claim 1, wherein the insert is aplastic insert, and wherein the passageway means is an annularpassageway in the disklike central portion of said diaphragm andcommunicates with said screening holes and has communication with saidcentral bleed hole leading through said insert.
 3. The solenoidcontrolled fluid pressure operated diaphragm shutoff valve of claim 1,wherein the insert is a plastiC insert, and wherein the passageway meansbetween said circumferentially spaced screening holes leading throughsaid diaphragm and said single bleed hole leading through said insertcomprise an annular passageway in said insert having communication withsaid bleed hole in said insert and opening to said diaphragm and havingcommunication with said circumferentially spaced screening holes.
 4. Thesolenoid controlled fluid pressure operated diaphragm shutoff valve ofclaim 1, wherein the circumferentially spaced screening holes leadingthrough said diaphragm comprise a screen molded in the disklike centralportion of said diaphragm and an annular passageway leading from saidscreen and having communication with said bleed hole leading throughsaid insert.
 5. The solenoid controlled fluid pressure operateddiaphragm shutoff valve of claim 1, wherein the communicating passagewaymeans between said screening holes leading through said diaphragm andsaid bleed hole leading through said insert, comprise an annularpassageway in said insert opening to said diaphragm and a screen in saidannular passageway and having communication with said screening holesleading through said diaphragm.
 6. A flexible diaphragm valve made froma resilient material and particularly adapted for a pilot controlledpressure operated valve, comprising, a diaphragm having a peripheralsealing portion, an inner annular bellowslike portion and a centraldisklike portion forming a shutoff valve, a rigid plastic insert backingup said central disklike portion and sealed thereto, said annularbellowslike portion extending about the periphery of said plastic insertand outwardly therefrom and terminating into said peripheral sealingportion, said insert having a central guide boss leading through saidcentral disklike portion of said diaphragm, having a central pilotorifice leading therethrough, and having one bleed hole spaced radiallyof said central pilot orifice and of a lesser cross-sectional area thanthe cross-sectional area of said central pilot orifice, a plurality ofcircumferentially spaced screening holes leading through said disklikeportion of said diaphragm, and communicating annular passageway meansbetween said screening holes and said bleed orifice.
 7. A flexiblediaphragm in accordance with claim 6, wherein the communicatingpassageway means is an annular passageway in the insert and opening tosaid screening holes and having communication with said bleed orifice.8. A flexible diaphragm in accordance with claim 6, wherein thecommunicating passageway means is an annular passageway in said centraldisklike portion of said diaphragm and opening to said insert.
 9. Aflexible diaphragm in accordance with claim 6, wherein the screeningholes in said diaphragm comprise a screen molded in said centraldisklike portion of said diaphragm and an annular passageway in registrywith opposite sides of said screen and with said bleed hole leadingthrough said orifice.
 10. A flexible diaphragm in accordance with claim6, wherein the communicating passageway means comprises an annularpassageway in said insert, opening to said disklike portion of saiddiaphragm, and having a screen extending thereabout.